The present invention relates generally to telecommunications systems and more specifically to call information queries.
A modern telecommunications network generally includes at least one national or regional service management system (SMS), at least one local SMS, at least one service control point (SCP), at least one signal transfer point (STP), at least one tandem switch, and at least one service switching point (SSP). A national or regional SMS includes a master database that contains information for a given service or application. The information contained within the national or regional SMS can be concurrently utilized by multiple networks that are operated by different local telephone service providers. A local SMS stores information and acts as an interface between the national or regional SMS and an SCP. An SCP can include an SCP data base that can contain call information consisting of call routing and/or call rating information. The call information contained within an SCP database can be downloaded from the national or regional SMS via a local SMS. Additionally, an SCP receives queries requesting the return of call information. These queries are generated by an SSP. An SCP responds to the query by providing call information to an SSP.
An SSP comprises a high speed switch that transfers voice and data communications within the network. A central office is a call routing center that contains one or more switches that may or may not be equipped with intelligent network (IN) software or advanced intelligent network (AIN) software. An SSP comprises a central office containing one or more switches that is/are equipped with either IN or AIN software. Both the IN and AIN software equipped SSPs can generate queries. Queries are generated when certain predetermined conditions or thresholds are satisfied. When the conditions or thresholds are satisfied, a trigger within the IN or AIN software equipped SSPs is activated which in turn generates the query. Queries are requests for information associated with a telephone number that are transmitted from an SSP to an SCP database. Queries can contain both the telephone number for which associated information is requested and additional data that identifies the type of information that is requested. An STP comprises a high speed switch that transfers signaling commands within the network. An STP transfers queries and responses between an SCP and an SSP. An STP also transfers control signals between networks. A tandem switch transfers voice or data communications between networks.
A service provider typically utilizes a telecommunications network, as described above, to provide telephone service to its customers within a local network. A local network generally comprises the telecommunications network described above and is operated by an individual service provider. The local network typically has geographic boundaries and can contain one or more SSPs. Local networks operated by different service providers can have overlapping geographic boundaries. However, each service provider maintains control over the components that comprise the local network.
Each of the SSPs within the local network provide multiple customers with access to the network. Accordingly, individual customers gain access to the network through one of the SSPs. Each customer is assigned a unique ten digit telephone number which enables calls to be routed to them via their designated SSP. The first six digits of the telephone number, the NPA/NXX, identify the specific SSP that the customer is assigned to and thus facilitates the routing of calls to the customer. Each service provider maintains call routing information that is associated with each ten digit telephone number that also facilitates the routing of calls to the customer. The call routing information indicates the customer's assigned SSP and identifies the location of the customer within the network. Each service provider also maintains call rating information to facilitate the proper rating of calls placed to a customer. The call rating information identifies the location of the customer and is used to calculate the cost associated with terminating a call to the customer. Individual customers are typically assigned to a specific SSP based upon the customers' geographic location. The SSPs with a service provider's network are utilized to provide customers with access to the network.
Protocols are utilized to ensure that communications both with local networks and between local networks can be completed seamlessly. Global protocols are implemented by service providers to ensure that communications between service providers occur properly. Currently, global protocols are being established that allow information to be shared by and exchanged between multiple service providers. These global protocols include specifications regarding the routing of calls. These global protocols may also specify the format of information maintained in databases and the manner in which information in databases can be accessed. Specifically, the global protocols may limit or restrict the number of queries that can be performed for a given telephone number during the completion of a call. These global protocols also reflect the referred practices of sharing information amongst service providers and restricting modifications to this information as well as limiting the access to this information by limiting the number or queries that can be performed.
One such global protocol is embodied in service provider number portability (SPNP). Service Provider Number Portability (SPNP) is currently under development by several network hardware and software providers and will allow customers to retain their existing ten digit telephone number when they change from one service provider to another service provider. According to the SPNP specifications, when a call is placed by a calling party to a called party, the SSP that connects the calling party to the local network (calling party's SSP) must first determine whether the call is placed to a telephone number (called party's telephone number) that has potentially been transferred from one service provider to another service provider. If the number has potentially been ported, the calling party's SSP will launch a query to its local SCP database to obtain information on where to route the call.
The query contains both the called party's telephone number and other data that identifies the type of information, corresponding to the telephone number, that the SSP is requesting. One common request included within a query is for call routing information associated with a telephone number. Upon receipt of the query, the local SCP will search its database to locate call routing information associated with the called party's telephone number. If such information is found, it is transmitted by the SCP to the calling party's SSP. Once the call routing information is received from the local SCP database, the calling party's SSP forwards a special call-setup signaling message to the other SSPs in the call path to advise them that a query has been performed. The other SSPs that are in the call path may include SSPs that are within a different local network and are operated by a different service provider. Bit m of a Forward Call Indicator (FCI) field, which is included within the call-setup message, is used as a query indicator to signify whether a database query has been performed. The call-setup message also identifies where to terminate the call.
The technical requirements that have been documented to support the SPNP specifications expressly state that once a database query has been performed, no additional queries need be performed regardless of the number of subsequent SSPs involved in the call path. Each SSP within the call path can determine whether a query has been performed by analyzing bit m of the FCI. Thus, according to the SPNP specifications, once a query has been performed by a SSP, no other queries can be performed by any other SSP.
The implementation of global protocols such as SPNP results in undesirable limitations. First, every service provider that implements a global protocol must agree and adhere to the predetermined requirements of the protocol. Some of the protocol requirements include: the type of information contained within call information databases; the format of information within the call information databases; and the manner in which call information can be accessed by different network components. These global protocols also limit a single service provider's ability to modify the protocol because the changes must be accepted and implemented by all the service providers that adopt the protocol. Moreover, these changes must be implemented in every local network operated by each service provider that adopts the global protocol. Additionally, the global protocols, such as SPNP limit the number or queries for a single call. Accordingly, these protocols restrain an individual service provider from accessing additional information through the use of additional queries for a single call.
A service provider who wishes to introduce new service that requires a modification of a global protocol, for example the existing format of call information within a database, may not be able to implement such a modification. Because global protocols such as SPNP require that all information be obtained from a single query, changes in information within a local network must be reflected in all the local networks that share information. Therefore, all of the service providers would have to modify their formats in accordance with the modifications implemented by the service provider that seeks to introduce a new service. An individual service provider, however, has no way of mandating that other service provider's accept or implement the desired modifications. Accordingly, there is no way for an individual service provider to ensure that a protocol modification will be universally adopted. Therefore, a service provider cannot unilaterally introduce a protocol modification that may be necessary to provide a new service. Thus, a service provider may be limited in services that it can introduce. A system is needed that allows a service provider to unilaterally introduce new services requiring modifications of global protocol parameters while still supporting the existing global protocols.